Vincenzo Gianferrari Pini wrote:
Hi everybody,

The last weekend I moved the mail service of my company to James-2.1.

There are about 220 users, very active , generating about 120
inbound/outbound messages per hour, and about 2 pop3 requests per second
during peak hours.

On a server class Pentium III biprocessor with 2x350 MHz, > 512 MB Ram under
Windows 2000 Server SP3, everything works great and fast (5-6% CPU per
processor). James runs as a Windows service.

But after perhaps some hours, suddenly CPU goes up to about 50% per
processor (very balanced 50/50) and never goes back again. All such cpu is
on the James process (shown as java). Performance continues to be ok from
the end-user perception (nobody perceives anything), but there is something
wrong going on. The only way to fix the situation is to shutdown and restart
James.
I have to think this is some scheduler getting stuck in some loop, but can't say for sure. Peter might have a better idea since he did most of the refactoring for performance improvements.

If possible, what would be great is to try to run the system with a profiler. If you don't have a commercial one handy (you can often get a free 30-day trial of one), you can at least do the free text profiling that comes as part of the JDK. The newer JVMs don't get slowed down too much by this, and if normal traffic only is using 5-6% CPU, hopefully it won't be noticeable.

If you can get it running with acceptable performance in a profiling mode, then when it goes into the high-CPU rate, you could profile the JVM to see what threads and what code are running hot.

Not sure how comfortable you are doing any of this, but unfortunately it's one of those infrequent bugs that are often hard to diagnose without additional info.

--
Serge Knystautas
President
Lokitech >> software . strategy . design >> http://www.lokitech.com
p. 301.656.5501
e. [EMAIL PROTECTED]


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